Block copolymers



United States Patent 0 s,1s9,ss4 BLOCK CQl OLYR lERS Kenzie Nozaki, El Cerrito, cane, assignor to Shell Gil Company, New York, N.Y., a corporation of Delaware No Drawing. Filed June 22, 1961, Ser. No. 118,772

16 Claims. (Cl. 260--881) This invention relates to a new type of copolymers.

More particularly, the invention relates to new block copolymers and a method for their preparation.

Specifically, the invention provides new and particularly useful block copolymers comprising copolymers wherein the macromolecules are made up of two different linear segments joined in an end to end arrangement, the first segment being made up or" linear polymer of certain organic compounds containing a CH =C= group, and the other segment being made up of a polymer of a dissimilar monomer containing at least one polymerizable ethylenic group. A process for preparing these new block copolymers is also provided.

This application is a continuation-in-part of my copending application Ser. No. 566,774, filed February 21, 1956, now US. Patent No. 2,991,269, which in turn is a continuation-in-part of application Serial No. 270,278, filed February 6, 1952 now abandoned, which in turn is a continuation-inpart of application Serial No. 60,416, filed November 16, 1948 now abandoned.

Attempts have been made in the past to improve the properties of many of the homopolymers of the unsaturated monomers by copolymerizing the said monomers with various dissimilar compounds, the homopolymers of which display the desired superior properties. These copolymers have been prepared heretofore by merely mixing the unsaturated compound with the desired dissimilar monomer and then subjecting the resulting mixture to polymerization conditions, such as heat, light and catalysts. Ylhen combined under these conditions, the two monomers usually add to the polymer chain in a more or less random fashion and the resulting polymer chains are made up of a very complicmed arrangement of the two kinds of monomers. Copolymers prepared from monomers A and B, for example, will have the A and B units arranged in some such order as ABAABBBABBAABB. This method of producing the desired copolymers is not entirely satisfactory. It has been found, for example, that when the monomer units are distributed throughout the polymer chains in the above-described manner they fail to impart the properties of their corresponding homopolymars and the resulting copolymers many cases possess an entirely different set of properties. Furthermore, as there is no definite control over the order in which the monomers add to the polymer chain, the copolymers produced by this process rarely, if ever, have the same molecular structure or physical properties and standardization of the copolymers and their applications is quite diilicult.

It is, therefore, an object of the invention to provide a new kind of copolymer. It is a further object to provide a new type of copolymers which possess many (1 the characteristic properties of the homopolymers of the individual monomers making up the said copolymer. It is a further object to provide a new type of copolymer having many unusual and beneficial properties. it is a further object to provide new copolyrners having improved plasticizing properties. It is a further object to provide novel segmented copolymers having. unexpected properties as detergents, dispersing agents and the like. It is a further object to provide a new block copolymers having improved strength. It is a further object to provide new block copolymers which have substantially uniform molecular weights. It is still a further object to provide a new block copolymers from allrenes and cycloalkene.

to the polymer through a primary chemical bond.

These and other objects of the nvention will be apparent from the following detailed description thereof.

It has not been discovered that these and other objects may be accomplished by the new block copolymers of the invention comprising copolyniers wherein the macromolecules are made up of two diflerent linear segments joined in an end to end arrangement, the first segment being made up of a linear polymer of an organic compound containing 'a single CH=C= group, and the other segment being made up of a polymer of at least one monomer containing at least one polymerizable ethylenic group, one of V the latter monomer or monomers being dissimilar to the monomer unit in the first segment. These new copolymers are prepared by a novel process comprising adding a preformed linear polymer which is substantially free of carbon-to-carbon:unsaturation and has a molecular weight of at least 59,000 to a liquid medium containing an ethylenically unsaturated monomer which is dissimilar to the monomer unit contained in the preformed polymer,

and then subjecting the resulting mixture in an inert a mosphere to mechanical agitation to degrade the said preformed polymer. This process is based on the unex ected discovery that when a linear polymer of high enough molecular weight is subjected to a mechanical agitation treatment of considerable intensity, the polymer chains are broken to form polymer free radicals and when polymerizable ethylenically unsaturated monomers are brought in contact'with these free radicals, there is an addition of the said monomers to the polymer chains. The resulting copolymers thus possess an entirely different structure from the above-described conventional type polymers. The copolymers prepared by the process of the invention are made up of one section of the inducing polymer joined to a section of a polymer of the dissimilar monomer. Thus, the copolymer prepared by this process from an inducing polymer of A in monomer B may be represented as having the structure AAAAAABBBBBBBBB.

The diiierent molecular structure of the copolymers of the present invention as discussed above endows them with properties which are entirely different from those possessed by the conventional copolymers. As indicated above, the conventional copolymers lose the characteristic properties of the homopolymers ofthe monomers making up the said copolymers and assume properties which are entirely different. The copolymers of the present invention, on the other hand, retain many of the characteristic properties of the homopolymers of the individual monomers. A copoiymer made up of a segment of polyacrylonitrile joined to a segment of polystyrene produced by the process of the invention will, for example, possess the characteristic properties of both polystyrene and polyacrylonitrile.

An important application of the process of the invention is its use in the production of internally plasticized polymers, i.e., polymers wherein the plasticizer is joined The production of this type of polymer is accomplished by selecting as the inducing polymer, i.e., the preformed poly mer, a polymer which is softer and more flexible than the polymer of the added monomer, such as polyvinyl acetate, and using as the added monomer a compound which would ordinarily form a hard, brittle polymer, such as vinyl chloride, or the inducing polymer selected may be one that is hard and brittle and the added monomer may be one that forms the softer, more flexible polymer. In either case, the resulting product is a polymer that possesses substantially all the desired properties of the brittle polymer and the flexibility of the soft, flexible polymer. As the piasticizer is chemically bound in the molecule,

0 there is no danger of its loss through migration or volatilization.

A further important application of the process of the oneness r 3 invention is its use in the preparation of polymers having unexpected solution behavior. Polymers having the unexpected property of having solubility in both water and oil may be obtained by the novel process, for example, by employing as the inducing polymer a hydrocarbon polymer, such as polyisob'utylene, polystyrene, etc., and as the unsaturated monomer a compound having groupsthat have water soluble characteristics or. could be converted to groups 'having'water soluble characteristics, such as; vinyl acetate, acrylonitrile, methyl methacrylate, and the like, or alternatively by employing 'a polymer, having water'soluble; characteristics or being able to be converted to a water soluble polymer as the inducing agent, and the V hydrocarboncornponent as the unsaturated monomer. Copolymers prepared in this manner are particularly'useful as detergents and as dispersing agents forpreparing suspensions and emulsions of various components, such as metal oxides, that will not precipitate either inaqueous or hydrocarbon systems. V V V Still another important application of the process of the invention is its use in the production of copolymers ifrom monomers that have heretofore never been able to be polymerized together. By the use 'of the process of the invention, for example, it is now possible to copolymen'ze components, such as cellulose derivatives, linear polyamides, polyesters, and monomeric compounds as isobutylene,- ethylene, and the like, with many components with which they have heretofore never been able to be combined. Additional advantage, of the process is found ins the fact that it may be accomplished in the absence of cata lysts and relatively high temperature and yields products of higher quality and more uniform molecular weight.

The copolymers of the present invention are distinguished in structure and properties from the copolymers prepared by forming a prepolymer of a polyethylcnically unsaturated monomer, such as piperylene, and then polymerizing another monomer at the remaining unsaturation in the prepolymer molecule. As the unsaturated prepolymer will possess unsaturated linkages in the main chain, such as and/or in the side chains, such as the resulting copolymer will always have the dissimilar" monomers adding on at the side of the mainpolymer r chain and the product will be a highly branched copolymer having a structure, such as 7 II it? it BIB'B [ll BB1? B wherein A is the monomer. unit derived from the polyunsaturated compound and Bis the monomer unit of the dissimilar monomer. Y

7 The copolymersi prepared from the prepolymers of the polyunsaturated compounds, such as piper'ylene, as'described above, will not have any of the superior proper- V ties of the segmented copolymers of the present inven-' tion; Such copolymers will have the dissimilar monomers distributed along the main polymer chain'and thef" propertieswill generally be the same as those of the.

conventional copolymer which are preparedby mixing the monomers at-thebeginuing' of the polymerization. Fur-,

patibility characteristics than as shown in the example at the end of the specification.

The preformed polymer to be used in the process'of the'invention may-be any polymer which has a linear structure, i.e., is not cross-linked, and is substantially free of aliphatic carbon-to-carbon unsaturated linkages,

i.e., unable to undergo further polymerization with"un-' i V saturated monomers when heated .in thepresence of pera oxide catalysts; As noted above, the preformed polymer,

10' of'free radicals formed when thepolyrner is broken,'andi undergoes polymerization the present process by means the polymerization is not due to .the presence of'any un saturated linkage in the molecule itself. 7 1

The preformed polymer may be one that occurs naturally or one that has been produced .synthetically.' i'rhe polymer may be a homopolymer, copolymer or interpolya mer. If the preformed polymers are synthetic-they may be producedby any suitable method. They'may. be pro-l duced, for example, by addition reactions, condensation reactions, and the like. The reactions may be energized if desired by light and/or heat and may be accomplished in the presence of any type p'olymerization catalyst, such J as peroxides, peracids, persalts, peresters, metals, 'inor ganic salts, Friedel-Crafts type catalystsQand -the like.'

The polymers maybe prepared by bulk polymerization,

in a solvent solution or in an aqueous emulsion or aque V ous suspension. Polymers prepared by a previousdperation of the processof the present invention may also be utilized.

Examples of the preformedpolymers that may be' 'used in the process of the invention'are cellulose esters and cellulose ethers, such as cellulose acetate, cellulose'nitrate', cellulose propionate butyrate, cellulose acetobutyrate,

eythl cellulose, butyl'cellulose, and propyl cellulose; phenol.

aldehyde condensation polymers, such as-phenol-formaldehyde polymers, phenol acetaldehyde; polymers, and resorcinol-formaldehyde polymers; polysulfide polymers, and the like; the vinyl polymers, such as polyvinyl chloride, polystyrene, polyacrylonitrile, and the lik'eg linearf alkyl resins, such as the polyesters of glycol and phthalic acid, 1,3-pentanecliol and succinic acid, glycol and 'glutaric' acid, and the like; linear polyamides, such as the one obtained by reacting'trimethyladipic acid with hexamethylene-diamine; polymers of ethylene oxide and tetrahydrofuran; polymers of the carbonic acid esters, of the 3 unsaturated diols, such as butadiene-3,4 carbonate, polymers of the unsaturated esters of the unsaturated acids,

such as diethyl fumarate, diethyl maleate, and the like. 7

A preferred group of preformed relatively high molecular Weight, linear polymers'to beused in the-process of the invention arethe homopolymers, copolymers and 'interpolymers of the polymerizable olefinic compounds conraining a C=C group suchas the polymers of maleic acid and maleic acid esters, tetrahaloethylenes, vinyl-type 1 compounds, etc. Particularly preferred are the polymers of monomers containing-at least one CH =C group.

Examples of the'polymers of monomerscontaining at 7 least one CHFC: group are the polymers ofiisobutyl acrylate, butyl methacrylate, and propy l 'acrylate; the;

polymers of th e vinylidene halides, such as vinylidene' F" ther, copolymers prepared from the prepolyme'rs of the" polyunsaturated compounds will be highly branched and' thus'have'higher viscosity and poorer solubility and com ene, ethylene, propylene, octene-l, the aromatic compounds, such as styrene, alpha-methylstyrene, dichloro-' styrene, vinyl naphthalene, vinyl phenol and the-like.

Other examples are the polymers of the unsaturated acids, such as'acrylic acid and'the alpha-alkyl substituted acrylicacids, such as alpha-methyl acrylic acid'and alpha butyl acrylic acid, thepolyrners of the esters of these u nsaturated'acids, such as methyl acrylate, rnethyl'rrneththe unbranched polymers f chloride and vinylidene brorniderthe polymers of; the 'F :7

vinyl esters of inorganic acids, such as the'halogen acids, and hydr'ocyanic acid, as vinyl chloride, vinyl bromide,j acrylonitrile, and methacrylonitrilfpblymers of the lvinyl' esters of the monocarboXylic acids, such as vinylface'tatm- H vinyl chloroacetate, vinyl benzoateyvinyl, laurate', vinyl.

.valerate, and vinyl caproate; the polymers of the Vinyl;

ethers, such as vinyl ethyl ether, and the vinyl ketones,

allryl esters of acrylicacids andalpha-alkyl substituted.

acrylic acids wherein the alkyl radical in the alcohol portion of the ester radicalcontains from 1 to 6 carbon atoms and the alkyl radical substituted on the acrylic acid contains from 1 to 4 carbon atoms, the vinyl esters of the saturated'rnonocarboxylic'acids containing from 1 to 6 carbon atoms, the vinyl esters of the halogen acids, isobutylene, acrylon-itrile, methacrylonitrile, ethacrylonitrile, styrene, and alpha-methylstyrene. Examples of this particularly preferred group of preformed polymers are polyvinylidene chloride; polyvinyl bromide, polyvinyl fluoride, polymethyl .methacrylate, polymethacrylonitrile, polyisobutylene, polyacrylic acid, polyethacrylic acid, polyethyl acrylate, polybutyl acrylate, polystyrene, polymethylstyrene, a copolymer of 10% vinyl chloride and 90% vinylidene chloride, a copolymer of methacrylonitrile and 75% methyl methacrylate,

v a copolymer of 40% styrene and 60% vinyl chloride, a

'copolymer of vinyl fluoride and 50% ethacrylonitrile, an interpolymer of 5% methyl methacrylate, 30% methylstyrene and methacrylonitrile, an interpolymer of 30% vinylidene chloride, 20% vinyl chloride and 50% methyl methacrylate, and an interpolymer of 3% vinyl acetate, 40% vinyl butyrate, 30% methyl methacrylate, and 27% methacrylonitrile.

In case the process of the invention is to be used for the production of internally plasticized polymers as described above, the preformed polymers to be utilized may be those polymers which are softer, more fieidble than the preformed high molecular weight linear polymer. Examples of such polymers are the polymers of methyl methacrylate, vinyl acetate, vinyl propionate, Vinyl butyrate, vinyl chloroacetate, methyl acrylate, ethyl acrylate, butyl methacrylate, octyl methacrylate, n-dodecyl methacrylate, and methyl vinyl ketone.

Corning under special consideration as the linear polymer to be used in the process of the invention are the polymers of the aliphatic monethylenically unsaturated compounds containing from 2 to 10 carbon atoms, such as ethylene, isobutylene, octene-l, and the like, and mixtures thereof. 7 The polymers of isobutylene are particularly as the copolymers prepared therefrom are especially unique. While in some cases it has been possible to add a few isobutylene monomer-units to other monomers by the conventional processes, the products have generally been liquid conglomerates of little practical utility. The process of the invention, however, enables one to obtain valuable copolymers of isobutylene containing a much higher number, e.g., 75, 100 or more, of isobutylene units. Such product are solid resins which can be utilized for many important industrial apphcations, such as in the preparation of coating compositions, adhesive and impregnating compositions,self-sustaining films, solid plastic articles, and the like. 7

The aforesaid isobutylene copolymers are generally prepared by utilizing as the inducing polymer, a relatively high molecular weight polymer of isobutylene, such as an isobutylene homopolymer prepared by use of a Friedel- Crafts catalyst, and adding this polymer to the desired monomer as described hereinafter, such as the vinylidene halides, the vinyl halides, the unsaturated nitriles, the alkenyl esters of the saturated monocarboxylic acids, the alkyl esters of the ethylenically. unsaturated acids, and the vinyl aromatic compounds, and subjecting the resulting mixture to the desired mechanical treatment to break the polyisobutylene chains.

The molecular weight of the preformed polymers should 6 be sufliciently high to permit a degradation of the polymer molecule when the said polymer is subjected to the subsequent agitation treatment. The molecular weight of the preformed polymers used in the process of the invention will, therefore, vary over a considerable range depending upon the ease with which the individual polymer may be degraded, the intensity of the agitation treatmentQetc. in some cases polymers having molecular weights as low as 5x10 may be used in the process. In other cases polymers having a molecular weight as high as 9x10 or higher may be used. The preferred polymers to be used in'the process have molecularweights between 7.5 X 10 and 7 x10 These molecular weights weredetermined by measuring the intrinsic viscosity of the polymer in solution and calculating the molecular weight as discussed by P.-I. Flory in the Journal of the American Chemical Society, 372 (1943).

The monomers to be mixed with the above-described polymers may be any of the polymerizable organic compounds containiug at least one polymerizable ethenoid group, i.e., organic compounds containing at least one polymcrizable C=C group. These polymerizable olefinic compounds may be exemplified by maleic and fumaric acids and their esters, the tetrahalo-ethylenes, the esters of the unsaturated diols, etc. Preferred polymerizable olefinic compounds to be employed in the process of the invention are the vinyl-type compounds, i.e., those polymerizable organic compounds containing at least one CHFC group in their molecule. Examples of such monomers are the butadienes, such as butadiene- 1,3 2,3-dimethylbutadiene-l,3, piperylene, isoprene, chloroprene, the aromatic compounds, such as styrene, alphamethyl-styrene, dichlorostyrene, vinyl naphthalene, vinyl phenol and the like. Other examples of the vinyl-type compounds are the unsaturated acids, such as acrylic acid and the alpha-alkyl substituted acrylic acids, such as alpha-methyl acrylic acid and alpha-butyl acrylic acid; the esters of these unsaturated acids, such as methyl acrylate, methyl methacrylate, butyl methacrylate, and propyl acrylate; the vinylidene halides, such as vinylidene chloride and vinylidene bromide; the vinyl esters of inorganic acids, such as the halogen acids, and hydrocylanic acid, as vinyl chloride, vinyl bromide, acrylonitrile, and methacrylonitrile; the vinyl esters of the monocarboxylic acids, such as vinyl acetate, vinyl chloroacetate, vinyl benzoate, vinyl laurate, vinyl valerate, and vinyl caproate; the vinyl esters of the polycarboxylic acids, such as divinyl succinate, divinyl adipate, vinyl allyl phthalate, vinyl rnethallyl pimelate, and-vinyl methyl glutarate; the vinyl esters of the unsaturated acids, such as vinyl acrylate, vinylcrotonate, and vinyl methacrylate; the vinyl ethers, such as vinyl ethyl ether, vinyl butyl ether, and vinyl allyl ether; and the vinyl lretones, such as vinyl butyl ketone, and vinyl ethyl ketone. The group also includes the allyl derivatives, such as the allyl esters of the monocarboxylic acids, as allyl acetate and allyl butyrate; the allyl esters of the polycarboxylic acids, such as diallyl phthalate, diallyl adipate, and diallyl succinate; the allyl esters of the inorganic acids, such as allyl chloride, methlyl chloride, etc.; the allyl esters of the unsaturated acids, such as allyl acrylate, allyl crotonate, and methallyl methacrylate, and the allyl ketones, allyl ethers, and the like. e

'A preferred group of vinyl-type compounds are the members of the group consisting of the vinylidene halides,

acrylic acid and alpha-alkyl substituted acrylic acids wherein the allryl radical containsfrom *l to 4 carbon atoms, the alkyl esters of acrylic acid and alphaealkyl subsituated acrylic acids wherein the allcyl radical in the alcohol portion of the ester radical contains from l to 6 carbon atomsand the alkyl radical substituted 'on the acrylic acid contains from 1 to 4 carbon atoms, the vinyl esters of the acrylic acid and alpha-alkyl substituted acrylic acid wherein the alkyl radical contains from 1 to 4 carbon atoms, the vinyl esters of the saturated monocarbe added to the reaction may vary over a considerable boxylic acids containing from 1 to 6 carbon atoms, the 7 Molecular oxygen will inhibit the polymerization rcac-. vinyl esters of the halogen acids, isobutylene, acrylonition and it is usually desirable to=removethe oxygen 'tr-ile, "methacrylonitrile, 'ethacrylonitrile, styrene,and' from -the reaction chamber beforev the degradation? is alpha-methylstyrene; Examples of this preferred group of commenced; In the case of a few monomersfsuch. as vinyl-type compounds are vinylidene chloride,1vinylidene styrene, however,.-small. quantities of oxygen may 'be bromide, vinylidene iodide, methyl acrylate, butyl'acrys tolerated. The removal of the oxygen maylbe acconrslate, butyl alpha-butyl acrylate, vinylVacrylate, vinyl ace plished by any suitable method.,ltis prefer-ably accom tate, vinyl butyrate, vinyl methacrylate, and the like. pli-shed by freezing theVmixture? of preformed polymer In case the monomer is to be added to produce a plasand monomer and evacuating i-t'he-"reaction chamber by ticizing elfect on the resulting polymer the ones selected 1 means of a pump. In some casesitimay'be desirable to. will be thosegwhich form polymersiwhich are softer and replace the withdrawn oxygen with an inert gas'-,-'isuch as. V *moreflexible than the preformed high molecular weight, 7 nitrogen, methane, carbon dioxide,andthe' like, I j V linear polymer, such'as methyl methacrylate, vinyl ace The process of the invention maybeaccomplishedlin 'tatefvinyl propionateQvinyl butyra-te, methyl .acrylate, the'presence or absence of'lighti' As light has an a c-Q and the like}. V celerating effect on the polymerizationof sometypesof Block copolymers of the invention which are particumonomers, itmay be desirable somecases to conductlarly outstanding, especially because of the attractive plasthe reaction in the-presence of liglit in order to'increase V tic articlesthat can be molded therefrom are those wherethe polymerization rate. a V in the initial polymer to be broken is selected from the Tne agitation treatment appliedV;to the deoxygenated group consisting of polymers of esters of ethylenically-un reaction mixture may be any suitable treatmentiiwhich saturated monohydric' alcohols and carboxylio acids, alwill apply sufficient strain and tensions on the bonds' of kenes, vinyl halides, vinylidene halides, ethylenically un-- the polymer to breakthe polymer chains. Mechanical q a saturated nitriles, alkenyl ethers' and alkenyl ketones, and treatments, such as shaking, high speed stirring, milling, V the dissimilar monomerused in the process is one selected V grinding, gear and piston pumps, passage through filtei-s from the group consisting of esters of ethylenically'unand capillaries,are satisfactory. The'degradation of the saturated alcohols and carboxylic .acids, alkenes, vinyl preformed polymer, is preferably accomplished by passing halides, vinylidene halides, ethylenically J unsaturated the reaction mixture through variouslydesigned throttle nitriles, alkenylethers and 'alkenyl ketones. V values, or narrow orifices at high'linear velocity. For, '7 Corning under special consideration are block copolythis purpose an enclosed system and 'a circulating gear mers prepared from a segment selected from the group pump or diaphr agmpump 'capable of generating high consisting of polymers of alkenyl' esters of monocarbox hydrostatic pressures have proved very satisfactory. An

ylic acids containing up to 10 carbon atoms, alkenes conother preferred method comprises subjecting the reaction taining from 2 to 5' carbon atoms, vinyl chloride, vinylimixture to high speed stirring, e'.'g.; stirring'at the rate of dene chloride, compounds of the formula RCN wherein .V about 4600 rpm. V V R is;an,alk'enyl radical containing upto 8 'carbon'atoms Theamount of shear stress'to be applied'to the reaction and especially acrylonitrile, alkyl alkenyl ethers containmixture will vary over a considerable range depending 7 ing up to 8 carbon atoms and alkyl alkenyl ketones conupon the type of polymer to'be broken, e1g.,,whetlier it taining up to 10 carbon atoms, and the other segment is contains C-C, C'S C Q ,1 1-34...

a dissimilar polymer selected from the aforedescribed group.

The reaction is generally accomplished in a liquid me- .cient to [break the linear polymer. 'The shear Zstr'ess dium. The monomer or monomers toibe polymerized, if applied'by the usual slight shaking or stirring of the conliquid, may themselve form the medium or liquids, such tainers in the laboratory is'not sufiicient to bring about as Water, organic solvents or diluent s, such as benzene, the desired degradation. In general, the shear cyclohexane, xylene, hexane, diheptyl ether',.an'd thelike, stress applied to the solution should be that determined and mixtures thereof may be addcdto the reaction mixby thefollowing formula V V V ture. In most cases, it is preferred to use only the mond- V I v 9X10, V V

mer as the reaction mediumand to employ conditions 'T =dynes/cm. I

to maintain the monomerin the liquid phase. The me-' (i dium'need'notdissolve the polymer, but it has beenfound g that better results are obtained if there is at least' a partial dissolution of the polymer. V f j .The quantity of the preformed inducing polymer to wherein M.W. is the molecular weight of'the linear reactants, the minimum stress hould be determined by range. In most instances, it is desirable to keep the ,the formula amount' of polymcr'at a relatively low 'level so that there will. be more opportunity forgthe chains to be 14 n s read out and broken near the middle. If the medium 7 7 V yn S/cm.-

' becomes too' concentrated with respect 'tothe polymer, V f

.the'polymer chains may become entangled and'only those and more t m ,7 segments sticking out of the bundle may be broken- 2 lO T 'l 2 V Preferably the polymer isemployedin amounts varying n a W 2 P fr-om 0.5 to 10 narts per 100 parts of'rnedium and more? w 'M is I V ,7 l V v g V -molecular .wei ht of the linear preferably from Parts P 9 P i m s epolymer; Increasing the shear stress infer-eases the for-ma:

. V The arn lm 61531191112111" monomer er s 65 tion of polymer free radicals and this in turn increases the V the Ra -9 f W111 also Y J Y f f i rate of reaction, so fasterreaction ratesimay be obtained 7' -lf th e mono mer isjemployed as the l quid medium tor the by using shear strgcssas which arvihf considerable exesrs TQHCUOR, the amountof monomer will be relauvely'la-rge I of thoss described abnv. r it- I V p d t9 'Q the degyee of dilution" in The temperature at which the process maybe carried 3??? a Stepped soon a The '70 out may also vary considerably. .In general'temperatures i ff of q i d f 9 ranging from 0 C. to 25GC have proved satisfactory;

P y nin 8 mac-U011 fi 1 Particularly preferred temperaturesrange saweesoec; V a an t Solvent s ploy the amount of monomer and c. Atmospheric, superatmospheric, or, subat-V ,added- Willdepend generallyupon theamount of monomer imospheric pressures may housed in the process as desired:

etc., bonds, the molecular weight of the polyme n'the ViS -A 4O cosity of the solution, etc., 'buti-t should be "at lea'stsuffi V polymer. Preferably with" polymers having the main-1 Y chainconsisting chiefiyof C-C,'CS', "C '-O or -SS bonds, which polymers are present amounts varying from 0.5% to 10%,;by weight of the that'is to be added to the polymer chains. 7 The polymers formed inthe reaction may be recovered a V amass-4.

v by any suitable means, such as filtration, solvent extraction, dehydration and the like.

The process of the invention may be executed in any convenient type apparatus enabling the maintenance of the proper conditions and the introduction of the various reactants. The process may be carried out in batch, semi-continuous or continuous manner. For large scale production it is preferred to conduct the process in a continuous manner. in such an operation the preformed polymer and monomer or monomers will be continuously added and the polymers continuously removed fromthe reaction mixture. The operation of the processin a continuous manner is particularly desirable as suchianoperation presents much more stable conditions andthe composition of the resulting pol mers are more uniform and of better quality.

As described above, the copolymers produced by the process of the invention will generally be substantially colorless polymers havingfa uniform molecular weight. Plasticized compositions produced from the said polymers possess excellent strength and flexibility. The resins may be cut, milled, machined to produce the various articles of commerce, such as buttons, table tops, containers, and the like. In the molten or solvent solution the polymers, may be utilized in the preparation of impregnating agents, laminating agents, surface coatings, and thelike. They may also be subjected to extrusion and to injection and compression molding in the presence 'or absence of added diluents and plasticizers.

To illustrate the manner in which the invention may be carried out the following examples are given. It is to be understood, however, that the examples are for the purpose of illustration and the invention is not to be regarded as limited to any of the specific conditions cited therein.

The deoxygenation of the preformed polymer-monomer mixture in the following examples was accomplished by freezing the said mixture in liquid nitrogen, evacuating on an oil pump, melting, and repeating the step three more times.

As described above, the copolymers produced by the above-described process will be block copolymers, i.e., they are made up of two or more segments of polymers joined in an end-to-end arrangement, the first segment being made up of the preformed polymer of the alkenylsubstituted aromatic compound and the other segment or segments being made up of the polymer of the added monomer or monomers. The copolymers will have molecular weights ranging from about 10,000 to 750,000 (as determined by the intrinsic viscosity measurements as noted above) depending on intensiq of the mechanical agitation. In most cases, the molecular weights of the macromolecules will be substantially uniform due to the tendency of agitation to reduce the macromolecules to the same molecular weight level.

The new copolymers will preferably contain at least 5% by weight of the alkenyl-substituted aromatic compound, and preferably from 5% to 99% by weight of the said material. On a macromolecular structural basis, the molecules should preferably contain at least 5 units of the alkenyl-substituted aromatic compound and at least 5 units of the dissimilar monomer.

The block copolymers of the invention may be used for a variety of applications. They will be hard solid materials which can generally be molded or extruded to form attractive plastic articles. They may also be milled, machined, cut or otherwise formed into articles, such as buttons, table tops, containers and the like. In the molten or solvent solution the polymers .may be utilized in the preparation of impregnating agents, laminating agents, surface coatings and the like. They may also be subjected to extrusion and to injection and compression molding in the presence or absence of added diluents and plasticizers.

The apparatus used for shaking the reaction mixture in 10 the examples below consisted of a cylindrical glass vessel (5.08 cm. in diameter and 12.7 cm. in length) joined on one side to a vertical spring-loaded rod that was in sliding contact with a cam eccentrically mounted on the shaft of an electric motor. When the motor was on, the vessel containing the reaction mixture moved back and fort through a distance of 11.5 cm. 7 i

"in some of the examples cited below the polymerization has been conducted in the absence of light. This precaution was taken merely to indicate that the polymerization taking place in thereaction mixture was not 'due'to any accelerating affect of light.

EXAMPLE I l 149 parts of copolymer had beenv obtained. This represented a copolymer made up of asegment of polymetha- .crylonitrile and a segment of polyacrylonitrile.

(b) The same procedure as described in (a) was repeated using samples of polymethacrylonitrile having various molecular weights. The results areshown in the table below:

' Poly AN} Shaking "Total Poly Molecular Weight MAN, parts Time, polymer AN parts hrs.

l0 2, 500 160 138 128 50 2, 500 1G0 207 157 10 2, 500 160 44 34 5O 2, 500 160 263 213 1 MAN=methacrylonitrile. AN =acrylonitrile.

in this solvent indicating that substantially all of the 16.5% polymethacrylonitrile was attached to the polyacrylonitrile. a

EXAMPLE II This example illustrates the difference in structure and properties of the new type copolymers of the present invention as compared to graft polymers prepared by simply heating a prepolymer of a polyethylenically unsaturated monomer such as butadiene, isoprene or; piperylene, with a dissimilar monomer.

(A) 25 parts of natural rubber crepe havinga molecular weight of about 500,000 are dissolved in 1500 parts of benzene and 1500 parts of styrene are added thereto. Tubes containing this mixture are sealed in vacuo, darkened and a stress of 500 dynes/cm. applied by shaking the tubes at room temperature as shown in Example I.

After 200 hours, the shaking is stopped and the unreacted styrene and benzene solvent removed under vacuum. 50 parts of a solid copolymer containing a segment of polyisoprene (25 parts) to a segment of polystyrene (25 parts) is obtained." No separate homopolymer of styrene can be removed from the new copolymer by;known sol- 7 ing a single orifice which has a diameter between 0.005

to 0.01in. to degrade the polymethacrylonitrile. about 30 hoursith ere is weight of the polymer. 7 1 polymer made up of a segment vent precipitation methods so all of the styrene must be attached to the copolymer. (B) An old type'graft copolymer is prepared as follows: 50 parts of the natural rubber crepe described in (A) aboveis combined with 50 ,parts of styrene -in benzene and the mixture heated for Lfdays at 100 C. .Unpolymer ized material is then removedalong with the benzene. Asolid thermoplastic polymeric composition is obtained."

When subjected to solvent precipitationtechnique, a large 7 part of the polymer is recovered and identified as pure.

homopolymer ofstyrene' V r (C) The new type copolymerprepared in (A) above is compared with the polymer preparedin (B) The polyiner prepared in-(B).isn iuch more'brittle than the poly- 'merprepare d in (A) and has a low temperature brittle 1 point of at least C., below thatf of the polymerzof 7 Further, the 'polymerof (B) is insoluble in hexane which is a poor solvent for polystyrene homopolymer,

'wh ilejthe polymer produced in (Al is soluble in "that solvent. 7 V ,7

* ExAMPLn'nIf a stress'of about 500 dynes/cm. applied to the mixture by shaking as noted in Example I at the rate of about '300'strokes a minute. This reaction required a much more vigorous shakingas the methacrylonitrile was a'rela-' tively poor solvent A for polymethyl methacrylate. The

7 resulting product was 72.4 parts of a copolymer made f upof a segment of polymethyl methacrylate joined to' a segment of polymethacrylonitrile."

I The above process was repeated using 2500. parts of acrylonitrile in place of the methacrylonitrile. In,-;this case, the product was identified as a polymer comprising a segmentof polymethyl methacrylate joined to a segk ment of polyacrylonitrile.

EXAMPLE yr I 'About 10 parts of polymethylimethacrylate' having a A molecular. weight of 8.'7 10 .were added. to 2500 parts This example demonstrates that to obtain the new type V copoly'mer one must utilize polymers of high molecular weight, and that onecarmot obtain the copolymersby simply exposing low molecular weight polymers, such as disclosed in U.S. 2,317,859, to mechanical agitation.

to about The 'mer has a molecular weight of about 10,500. a

25 parts of the polymer. roduced above is combined with 1500 parts of styrene and 1500 parts of benzene.

Tubes containing'th'e mixture are sealed in vacuo, darkened and a stress of 500 dynes/ cm. applied by shakingat room temperaturef After 200 hours of shaking, the reaction mixture isr'emovedand separated'into a fraction 7 containing the initial polymer and substantially all of the initial 'unpolymerized styrene.

formation of polystyrene in the'initial polymeric'composition. This indicates that the'initial polymer was not of suflicient molecular weight to be broken into polymer free radicals. v r a 7 Exposure of the above reaction mixture to ultrasonic radiations at a frequency of 500 kilocycles under the same conditions also fails to cause any formation of the new type copolymer as 7 all the styrene was recovered unattached.

EXAMPLE IV 7 About 10 parts of polymethacrylonitrile having'amol;

weight of 5.4)(10 are mixedwith 1500-parts of monomeric vinylidene chloride and 1000 parts of cyclohexanone the polymer recovered. The resulting solid soluble poly- There is no detectable I 24 parts of polyisobutylene having a molecular weight of 2.2 l 0 prepared with'a Friedel-Crafts catalyst at 80 C. were added to 1500 parts of styrene and 1500 *and the resulting mixture is deoxygenated The mixture is then exposed to a stress of at least 500 dynes/cnr? by repeatedly forcing it at a pressure of about 1000 psi.

through a'uniticontaining a thin platinum sheet containin. In about a 20 fold increase in the The product-is identified as a of polymethacrylonitrile jointed to a segment of polyvinylidenerchloride.

, EXAMPLE v" AbfotitlO parts of polymethylmethacrylate having a 7 molecular weight-of 8.7 10 were added to 2500 parts 7 -of 'methacrylonitrile and the mixture deoxygenated.

V V ride were obtained. This polymer Tubes containing the mixture were sealed in vacuo and ment of polystyrene.

of styrene and the mixture deoxygenated. Tubes contain-1 ing the mixture were sealed in vacuo, and then. shaken at 330 strokes'a minute at room' temperature. The lresulting product was parts of a copolymer made up of i a segment of polymethyl methacrylate joined to a seg EXAMVPLEYVII, 1

About 6 parts of polystyrene havingamolecularweight, of 633x10 were added to 1500 parts of methyl moth acrylate and 1500 parts of toluene. Tubes containing the I mixture were sealedinvacuo, darkened, and then shaken at 330 strokes a minute at roomtemperature. After about 120 hours of shaking 128 parts of a copolymer made up of a segmentiof polystyrene joined to a segment of polymethyl 'methacrylate were obtained.

V EmMPLE VIII About 10 parts of polyvinyl acetate are added @1500 I 7 parts of toluene and 1500 parts of vinyl chloride Tubes containing the mixture are sealed in vacu'o, darkened, and shaken at 330strokes a minute at; room temperature. After hours a large yield of a copolymer of polyyinyl chloride and polyvinyl acetate is obtained. This internally plasticized copolymer is compared in. properties and flexibility with a conventional copolymer of vinyl acetate and vinyl chloride: The internally plasticized'copolymer possesses substantially the same flexibility as the conventional copolymer and in addition possesses. many of the more desirable characteristic properties of polyvinyl chloride not possessed by the conventional copolymera EXAMPLE IX,

parts of benzene; Tubes containing the 'mixture' were sealed inf-vacuo, darkened, and shaken at.3'3 0 strokes a minute at room temperature. After hours of shaking 53 parts of a solid copolymer containing a segment of polyisobutylene and a segment of polystyrene were obtained. The copolymer 'could be molded to form an attractive plastic article. 7 a

EXAMPLE X About 8 parts of polyisobutylene'havin'g amolecular weight of 2.2 1.0 prepared with a Friedel-Craftscatalyst i were added to 2000 parts of vinylidene chloride and'the mixture deoxygenated. Tubes containing the mixture were sealed in vacuo, darkened, and shaken 'at' 330 strokesa minute at room temperature. After one week of shak- 'ing 310 parts of solid copolyrner-containing a segment of polyisobutylene and a segment ofpolyvinylidenechlo:

to forma plastic article.

could. also. be molded EXAMPLE XII About 50 parts of polyisobutylene having a molecular weight of 2.2x 10 are added to about 2000 parts of vinyl acetate and 1000 parts of cyclohexane and the resulting mixture deoxygenated. The mixture is then repeatedly passed through a narrow orifice as shown in Example II. At the end of about 24 hours, a yield of 200 parts of copolymer had been obtained. The resulting product made upjof a segment of polyisobutylene joined to a segment of polyvinyl acetate is then subjected to mild hydrolysis to convert the acetate groups to hydroxyl groups. The hydrolyzed copolyrner shows unusual solubility characteristics as it has solubility in both water and oil.

EXAMPLE XIII About 50 parts of polymethyl methacrylate having a molecular weight of about 7.2 were mixed with 200 parts of vinyl chloride, and the mixture deoxygenated. Tubes containing the mixture were sealed in vacuo, darkened, and shaken at 330 strokes a minute at room temperature. At the end of 8 days of shaking, 215 parts of a solid copolymer comprising 50 parts of polymethyl methacrylate and 165 parts of polyvinyl chloride were obtained.

The copolymer possesses many of the physical and chemical properties of the polyvinyl chloride alone, and can be processed without the addition of any plasticizer to form flexible resins.

EXAMPLE XIV About 50 parts of polymethyl acrylate prepared by polymerizing 1 volume of monomer per 3 volumes of water containing .3% sodium lauryl sulfate and no catalyst (molecular weight approximately 500,000) were added to 2100 parts of vinyl chloride and the mixture deoxygenated. Tubes containing the mixture were sealed in vacuo and shaken at 330 strokes a minute at room temperature.

420 parts of a copolymer containing a segment of polymethyl acrylate and a segment of polyvinyl chloride were obtained. I

This process was repeated using 2100 parts of acryloni- V trile in place of the vinyl chloride; In this case the resulting product was a polymer comprising a segment of polymethyl acrylatejoined to a segment of polyacrylonitrile.

EXAMPLE XV About 10 parts of polyvinyl chloride having a molecular weight of 4.2 10 were added to 1000 parts of methyl vinyl ketone and 100 parts of cyclohexanone and the mixture deoxygenated. Tubes containing the mixture were sealed in vacuo and shaken at 330 strokes a minute at room temperature; 298 parts of a solid copolymer containing a segment of polyvinyl chloride and a segment of polymethyl vinyl ketone were obtained. .This polymer could be molded to form an attractive plastic article.

' EXAMPLE XVI An 0.4 solution of polymethacrylonitrile having a molecular weight of 5.4)(10 in acrylonitrile was deoxygenated by bubbling with oxygen-free nitrogen and sealed under a nitrogen pressure. The tubes containing the mixture deoxygenated. Tubes containing the mixture are sealed in'vacuo andshaken at 330 strokes a minute at room temperature. The resulting product is an interpolymer'containing a segment of poly-(vinyl chloride-methacrylonitrile) and a segment of polymethyl methacrylate. EXAMPLE vXVIII 1.0 parts of a copolyrner of 10 parts of polymethyl methacrylate and 55 parts of polystyrene prepared in Example VI above are added to 2500 parts of methacrylonitrile and the mixture deoxygenated. Tubes containing the mixture are shaken at about 500 stnokes a minute at room temperature. The resulting product is an interpolymer containing a segment of a poly(methylmethacrylatepolystyrene) copolymer and a segment of polymethacrylonitrile.

EXAMPLE XIX 10 parts of polymethyl methacrylate having a molecular weight of 8.7 x10 were added to a mixture of 500 parts acrylonitrile and 500 parts of vinylidene chloride. The resulting mixture is deoxygenated and shaken at 330 strokes a minute at room temperature. The resulting product is an interpolymer containing a segment of polymethyl methacrylate joined to a segment of a copolymer of acrylonitrile and vinylidene chloride.

EXAMPLE XX 8 parts of polymethacrylonitrile having a molecular weight :of 5.4 x 10 were added to 1000 parts of acrylonitrile and the resultant mixture was stirred at 4000 r.p.m. at 10 C. At the 'end of 30 minutes, 13.4 parts of a solid copolymer containing a segment of polymethacrylonitrile joined to a segment of polyacrylonitrile was obtained. At the end of minutes, the amount of copolymer had increased to 17.8 parts.

EXAMPLE XXI l0'parts of a linear polyamide of trimethyladipic acid and hexamethylenediamine (molecular Weight approximately 1x10 are added to 500 parts of acrylonitrile and 200 parts of cfyclohexanone and the resulting mixture stirred at 4000 r.p.m. at 20 C. At the end of 2 hours a large yield'of a copolymer made up of a segment of a polymeric reaction product of trimethyladipic acid and hexamethylene-dismine joined to a segment of polyacrylonitrile is obtained.

EXAMPLE XXII About 20 parts of ethyl cellulose are added to 500 parts of methyl methacrylate and 200 parts of cyclohexanone and the resulting mixture stirred at 4000 r.p.m. at 25 C. A copolymer made up of a segment of ethyl cellulose and a segment of polymethyl methacrylate is obtained as the final product.

methacrylate joined to asegrnent of polyvinylidene chloride, solid copolymers made up of a segment of polymethyl acrylate joined to a segment of polyvinylidene' chloride and solid copolyrners made up of a segment of polystyrene joined to a segment of polyvinylidene chloride were prepared by' adding polymethyl methacrylate, polymethyl acrylate and polystyrene separately. to 20 part portions of monomeric vinylidene chloride and shaking the resulting mixtures for one 'week at'330 strokes per minuteatroom jtemperature. The results are indicated in the table below; Each of thepolymers could be molded 1t; EXAMPLE XXIX Example XXVI is repeated with the exception that the V homopolymer'of vinyl butyl ketoneris replaced by each toform attractive plastic articles. 5 of the fOHQWiQgZ qm p ym of Vinyl ethyl ketom,

' V .Weight of Weight of Weight of Weight of Polymer Polymer Polymer and Monomer M01. Weight 1 Original Polymer in Control Formed by V Used'iu the Polymerization of the Poly- Polymer Vatterl Sample Shak ng merin 001.1 Shown in Week of" Which ((301.4.

' Col.1 Shaking Was not Less'CoL3 Shaken and 5) r amen i methacrylate vinylidene chlos.7 7 10.20 3. 13 0.08 V 2.25 P lyi nethyl acrylate vinylideno chloride 217133201X}.5 l 10.20 V 1.97 0.08 V 0.79 7 lolystyrene vinylidene ehlorlde; 6l3X10 V 0.20 4.87 0.08 .59

, 1 M EXAMPLE, XXIV i homopolymer of vinyl isobutyl ketone; and homply'mer V of methyl isopropenyl ketone, and a copolymer of 50% About- 20 Parts of a horpgpqlymer of vmyhdene chlovinyl ethyl ketone and 50% mal eic anhydricle; Related ride having a molecular weight of about 5 X 10 are added ult btained V to 100 parts of vinyl butyrate, 200 parts of cyclohexanone res S are 0 and the mixture deoxygenated. Tubes containing the miX- EXAMPLE XXX ture are sealed in vacuo and shaken at 330 strokes a a r V p v minute atroom'temperature. The resulting product is Examples X, XI and X11 are repeated with the ex identified as a segmented copolymermadeup of a segtion that the isobutylene polymer is .replaced'by. each of merit of poly(vinylidene chloride) joined to a'segment of the following: polyethylene having a molecular weight poly(vinyl acetate). This copolymer can be molded to of 5x10 and polypropylene having a molecular Weight form attractive plastic articles. 0t 4x10 Related results'are obtained. EXAMPLE XXV EXAMPLE XXXL 1 About 10 parts of a homopolymer-of vinyl butyl ether V 7 7 i f having'a molecular weight of about 4x10 are added to E amp c 'XXVH. is repeated with the exceptionth'at '1007 parts of vinyl propionate, 200 parts of cyclohexanone the'alkenyl ether'pblymer is replaced y a polymerbf ch and the mixture deoxygenated, Tub containing th 3 of the following: vinyl isopropenyl ether,vinyl amylether mixture are sealed in vacuo and'shaken at 330 strokes a' and vinyl p y 2 Re1at6dI $111t$ are Ob g. minute at room-temperature. Afterseveral days, the claim as my in n i n: tubes are opened and the unreacted monomer and solvent A new yp of p y wheffiin the removed. The resulting product is identified as a segment 6 Clues are made P of at least .Y dififil'fillt lineal segments. "copolyrner made up of a segment of poly(vinyl butyl loified in allynd d arrangement/[1'16 first-segfnfint ether) joined to a segment, of poly(vinyl propionate). 'beingalinear p ye r -th group conslstmgx This copolymer can be .moldedto form attractive plastic f esters of iethylenicany l fi ifi 316011015 'fi 'l i articles. r i V v rated monocarboxylic acids containing from 1 to 6 carbon 7 y'qMp XXV atoms, alkenes, vinyl halides;.vinylidene halides, ethylen-ir l I q V 4 Cally unsaturated nitriles, alkenyl ethers and allr'enyl kc About' 10 partsof a homopolymer of vinyl butyl ketones, and the second segment being a polymer of adis: 7 tone having a molecular Weightof 5x10 are added to similar monomer electe fr m ov ro p- 1000 parts of acrylonitrile. Tubes containingthismix- 2. A block copolymerras in claiml wherein the'fi-rstf ture aresealed in vacuo and a stress of 500 dynes/cm segment is a polymerof an alkene-l containing up to '10 applied to the solution by moving the glass vessel con- C H H'E V r 1 V 'taining the solution back and forth over a distance of 3.:A block copolymer as in claim 1 wherein' the first i 11 .5 cm. at the rate of about 300 strokes aminute. After g snt ..P y Y I i F a "several days; the tubes are opened and. theunreacted 4; A' bl'ock copolymerras in claim 1 wherein thefirst monomer removed. The resulting product is a copolymer egment is a polymer of vinyl .ester ofa monocarb'oxylic made up of a segment of poly(vinyl butyl ket'one). joined acid Containing P to 3 carbon in an end-to-end arrangement with a segment ofpoly- '5. A block'copolymer as in claim 1 wherein the fi'rlst '(acrylonitrile); V I segment is a polymer of vinyl chloride 7 V a EXAMPLE 6. A blockxcopolymer as in claiml wherein the first V segment isapolymer of vinylidenje chloride, V 0 About 10 parts of a polymer of vinyl propyl ether'hav- 7. A block eopolymer as in; claim 1 'vhere-in' the' filrst, mg a molecular weight of about 6x10 are added'to 100 segment is a polymer ofacrylonitrile. i Q 7 parts of vinyl butyrateand 200 parts ofcyclohexanone and 8; A block c'opolyme'r as .'1i cl' 'im 1 whereinthelfirst the mixture deoxygenatcd. .Tubes containing the mixture segment is a polymer oi an alkenylalkyl ether containing V are sealed in vacuo andjshaken .at 330'strokes aJminute up to 8 carbon atoms. v i j V v :at room temperature. After several days, theftu bes are 9. A'bl-ock copolymer 'as in -claim 1 wherein the first opened and the monomer and solvent removed. The re segment is a polymer of an alkenyl alkyl ketone containing", suiting product is a 'copolymer'fmadel'up;of a segment a up to:-8 carbonatoms. 7 Q 'P i of poly(vinyl butyrate) joined to a segment'of poly (vinyl '10. .A block polymer made up f t fiiff m. j y: 'P PY fll K I 1 polymer segments joined =in an end me d arrangement} 5 V EXAMPLE mu r the first segment beingapolymerof "an alkene-lcontainy r i ing up to 3 carbon at-6ms,.and'the second seg mentibeing Examplem is repeated with the exception that. the a polymer of acrylonitrile; i 7 LL 'homop olymer or vinyl butyl ether is replaced by a co- 1111A block copolymer made up of two ditferentlineari polymer of 50% vmylbutylether and maleic anhydride. polymer segments joined in an end to end ar-rangemeng th'e Related results are'obtained. l V

first segment being a polymer of isobutylene, andlthe s'ecsneaeea ond segment being a polymer of a vinyl ester of a saturated monocarboxylic acids containing from 1 to 6 carbon atoms.

-12. A block copolymer made up of two different linear polymer segments joined in an end to end arrangement, the first segment "being a polymer of an alkene-l containing up to 8 carbon atoms and the second segment being a polymer of a dissimilar alkene-l containing up to 8 carbon atoms.

13. A block copolymer made up of tWo different linear polymer segments joined in an end to end arrangement, the first segment being a polymer of an alkene-l containing up to 8 carbon atoms and the second segment being a polymer of a vinylidene halide.

14. A block copolymer made up of two different linear polymer segments joined in an end to end arrangement, the first segment being a polymer of isobutylene, and the second being a polymer of vinyl chloride.

15. A block copolymer made up of two different linear polymer segments joined in an end to end arrangement, the first segment being a polymer of vinyl chloride, and

References Cited by the Examiner UNITED STATES PATENTS 2,123,599 7/38 Fikentscher et al. 260-17 2,317,859 4/43 Soday 2'60-880 2,338,741 1/44 Soday 260'880 2,538,779 1/5'1 Harrison et al. 260-879 2,991,269 7/6 1 Nozaki 26O--4 MURRAY TILLMAN, Primary Examiner.

WILLIAM H. SHORT, JAMES A. SEIDLECK,

Examiners. 

1. A NEW TYPE OF COPOLYMER WHEREIN THE MACROMOLECULES ARE MADE UP OF AT LEAST TWO DIFFERENT LINEAR SEGMENTS JOINED IN AN END TO END ARRANGEMENT, THE FIRST SEGMENT BEING A LINEAR POLYMER OF A MEMBER OF THE GROUP CONSISTING OF ESTERS OF ETHYLENICALLY UNSATURATED ALCOHOLS AND SATURATED MONOCARBOXYLIC ACIDS CONTAINING FROM 1 TO 6 CARBON ATOMS, ALKENES, VINYL HALIDES, VINYLIDENE HALIDES, ETHYLENICALLY UNSATURATED NITRILES, ALKENYL ETHERS AND ALKENYL KETONES AND THE SECOND SEGMENT BEING A POLYMER OF A DISSIMILAR MONOMER SELECTED FROM THE ABOVE-DESCRIBED GROUP. 